1. Field of the Disclosure
This disclosure generally relates to an input device and, more particularly, to an optical navigation device and a lift detection method thereof.
2. Description of the Related Art
In an image user interface, generally at least one input device is used to interact with a host, such as a personal computer. For example, it is able to use an optical mouse to move a cursor to a specific position and perform the icon selection so as to activate a specific application. According to the user habit, the optical mouse may be lifted off a work surface in order to change the position thereof on the work surface, but the cursor position is not desired to be moved during the optical mouse leaving the work surface. Therefore, it is necessary to stop the displacement detection once the optical mouse is lifted off the work surface.
The lift detection method of the conventional optical mouse is generally to dispose a sensing device, such as an impedance sensor, a capacitance sensor or a pressure sensor on a bottom surface thereof so as to detect the parameter variation before and after a lift motion. However, the additional sensing device can increase both the device cost and the power consumption.
Accordingly, the present disclosure further provides an optical navigation device and a lift detection method thereof that do not need the additional sensing device so as to reduce the cost. In addition, as the lift detection method of the present disclosure is implemented by algorithm, it may cooperate with conventional detection methods thereby improving the practicality.